Bugs Ride on the Wings of the Wind
Small animals can take advantage of wind to go long distances in remarkable ways.
Tiny paragliding beetle that lived with dinosaurs discovered in amber (Science Daily). Beetles have wings, but are not often known as being world travelers. This article talks about a tiny beetle that rides on the wind in a clever way:
Featherwing beetles are smaller than the period at the end of this sentence. They get their name from the feathery fringe on their wings that enables them to catch the air and float like dandelion seeds. And, it turns out, they go way back — scientists discovered a 99-million-year-old featherwing beetle preserved in amber, and they named it “Jason.”
The fossil beetle lived 99 million Darwin Years ago, the article assumes. Has it evolved since then? Well, Jason sported some pinstripe grooves on its body that living species don’t have. Other than that, it could pass for a plain-old modern featherwing beetle:
Overall, though, the researchers found that K. jason has a lot in common with featherwings alive today, meaning that the family of beetles evolved features like a tiny body size and fringed wings millions of years ago.
Flying spiders sense meteorological conditions, use nanoscale fibers to float on the wind (Science Daily). Would it terrify you to know that spiders can fly thousands of miles? Many species of spiders can engage in ‘ballooning,’ using strands of silk to catch the wind. Crab spiders, this article reports, are larger than ballooning spiders. And they have made ballooning an art form. They can even forecast the weather before planning a flight that may send them aloft for hundreds of kilometers.
Through a combination of field observations and wind tunnel experiments, they found that large crab spiders (Xysticus species), about 5 mm long and weighing up to 25 milligrams, actively evaluated wind conditions by repeatedly raising one or both front legs and orienting to the wind direction. At wind speeds under 3.0 m/sec (7 mph), with relatively light updrafts, the spiders spun out multiple ballooning silks averaging 3 meters long, before releasing themselves from a separate silk line anchoring them to the blade of grass from which they launched. A single spider released up to 60 fibers, most of them as thin as 200 nanometers. These fibers differed from a drag line, which has been known as a ballooning line, and were produced by a separate silk gland.
The authors concluded that ballooning spiders actively sense wind characteristics and launch only when the wind speed and updraft are within relatively narrow ranges, increasing the odds of a productive flight. According to the fluid dynamic calculations the authors performed using their wind tunnel data, the spider relies on updrafts that form in the light winds into which they launch, further ensuring a successful flight.
The paper with the details is in PLoS Biology: “An observational study of ballooning in large spiders: Nanoscale multifibers enable large spiders’ soaring flight.” The paper says they can fly as high as 4.5 kilometers above sea level on their long-distance flights. Sometimes they appear as the first colonists to land on newly-formed volcanic islands. The paper mentions nothing about evolution.
Painted lady’s roundtrip migratory flight is the longest recorded in butterflies (Science Daily). A new study confirms that the longest-flying butterfly is the Painted Lady, not the famous American monarch. And the route they fly passes over one of the harshest environments on earth.
Researchers were now able to demonstrate that painted lady butterflies return from the Afrotropical region to recolonise the Mediterranean in early spring, travelling an annual distance of 12,000 km across the Sahara Desert.
The new study completes the circuit of tracing this little butterfly’s world-record path, showing that the insects do make a complete circuit. As with the monarch, no one individual makes the whole circuit. It is completed over several generations. The descendants of the crossers have never made the trip before, yet like monarchs, know just where to go.
This butterfly species travels 12,000 km and crosses the Sahara Desert twice to seasonally exploit resources and favourable climates on both sides of the desert. Few species are known to perform annual long-range trans-Saharan circuits, and that of the painted lady is the longest migratory flight known in butterflies to date.
The Illustra Media film Metamorphosis: The Beauty and Design of Butterflies argued that monarchs, and all butterflies, defy Darwinian explanations. Their life cycles, including metamorphosis, are evolutionary dead ends, and their organs, wings, and instincts are paragons of intelligent design. This article, though, assumes that Darwin did it. The scientists were intrigued by “parallelisms in such a unique evolutionary adaptation.”
We want to enjoy the wonders of the animal world. Please keep Darwin out of it. He’s the fly in the ointment.